Key Takeaways
- Being turned down for bypass surgery does not mean nothing can be done — it means CHIP PCI needs to be evaluated separately.
- CHIP PCI (Complex High-Risk and Indicated Percutaneous Coronary Intervention) uses mechanical circulatory support — IABP, Impella, or VA-ECMO — to safely treat patients who can’t tolerate surgery.
- An ejection fraction as low as 20% does not automatically rule out CHIP PCI.
- Procedural success rates in experienced, dedicated CHIP programmes are commonly in the 90% range, even after a failed prior bypass.
- The right question isn’t “can I have surgery” — it’s “is my anatomy technically accessible via catheter, and can this heart tolerate the procedure with support?”
Being turned down for bypass surgery is not the end of the road. It’s the point where a different, more specific clinical question needs to be asked: is this person a candidate for CHIP PCI — Complex High-Risk and Indicated Percutaneous Coronary Intervention?
Every year, a meaningful share of patients referred to cardiac surgeons for coronary artery bypass grafting are not considered surgical candidates — usually because of severely reduced ejection fraction, significant kidney impairment, a prior bypass, advanced age, or a combination of serious comorbidities. These patients haven’t been refused treatment. They’ve been refused one specific treatment. CHIP PCI exists for exactly this group.
This page explains what CHIP PCI actually is, who qualifies, what makes it possible, what outcomes are realistic, and what to ask if you’ve been told surgery isn’t an option for you.
CHIP PCI Is Not Heroic Angioplasty
CHIP PCI isn’t a single procedure — it’s a category of complex, catheter-based coronary intervention for patients whose risk profile makes standard PCI considerably harder, or who aren’t candidates for surgery at all. It is disciplined, planned, and support-ready work, not improvisation under pressure.
The defining difference from standard PCI is haemodynamic management. A standard PCI patient can usually tolerate the brief interruption in blood flow during balloon inflation or stent deployment without their circulation destabilising. CHIP PCI patients often can’t. Their safety during the procedure depends on mechanical circulatory support — devices that maintain blood pressure and cardiac output throughout the case, giving the interventionist room to work carefully without the heart failing mid-procedure.
Why Surgeons Decline Bypass in the First Place
Cardiac surgery carries a quantifiable perioperative risk, typically measured using the EuroSCORE II and the STS Predicted Risk of Mortality. Heart Teams use these scores to weigh surgical risk against expected benefit, and several factors commonly tip that balance away from surgery:
| Low ejection fraction (LVEF below 25–30%) | The heart may not tolerate cardiopulmonary bypass — the heart-lung machine used during surgery |
| High STS / EuroSCORE | Predicted mortality above roughly 5–8% usually shifts the Heart Team away from surgery |
| Significant kidney impairment | CKD stage 3b and beyond raises surgical risk, particularly around fluid management and bleeding |
| Prior bypass surgery | Redo CABG means working around scar tissue and limited usable graft vessels — meaningfully higher risk |
| Frailty or advanced age | Patients with significant frailty or cognitive impairment face disproportionate surgical risk and slower recovery |
| Significant lung disease | Conditions like advanced COPD complicate coming off the ventilator after surgery |
| Diffuse distal disease | Sometimes there’s simply no good landing zone for a graft — a surgical limitation, not a PCI one |
Here’s the point that matters most: being turned down for surgery on risk grounds does not automatically mean PCI is off the table too. In many cases the anatomy itself is technically workable via catheter — the same reasons that ruled out surgery (low EF, kidney impairment, a prior bypass) don’t necessarily prevent treating the same vessel through the wrist or groin instead.
The Support Devices That Make CHIP PCI Possible
Intra-Aortic Balloon Pump (IABP). The most established support device, inserted through the femoral artery. It inflates during diastole to improve coronary perfusion and deflates during systole to reduce the heart’s workload. It offers modest support — appropriate for moderate left ventricular dysfunction or complex multivessel work — but it does not actively pump blood.
Impella. A catheter-mounted pump that actively unloads the left ventricle and can deliver several litres per minute of additional cardiac output, depending on the device platform used. In selected very-high-risk cases — typically very low EF — Impella-supported PCI may be considered by experienced CHIP teams when the anticipated haemodynamic risk exceeds what IABP or standard support can safely manage.
VA-ECMO. Full biventricular circulatory support, reserved for the most complex presentations — cardiogenic shock, severely reduced function in both ventricles, or situations where Impella alone isn’t enough. This is the highest tier of support and is used selectively, not routinely.
Dr. Arun’s CHIP PCI Decision Matrix
| Decision dimension | The question that has to be answered |
| Anatomy | Is the artery technically reachable, crossable, prepareable, and stentable? |
| Myocardium | Is there viable, hibernating muscle actually worth saving? |
| Ischaemia and symptoms | Is the blockage clinically significant enough to justify treating? |
| Surgical risk | Why exactly was CABG declined, advised against, or considered too risky? |
| Haemodynamic risk | Can this heart tolerate ballooning, atherectomy, and stenting with appropriate support? |
| Support plan | Does this case need IABP, Impella, dedicated anaesthesia, or a staged approach? |
| Exit strategy | If the primary strategy doesn’t work, what’s the bailout plan? |
This matrix is applied to every CHIP PCI case before it’s ever scheduled. If a centre can’t answer these questions specifically for your anatomy, that’s a sign to seek review elsewhere.
Who Actually Qualifies
CHIP PCI is generally indicated when three things are true together:
- There’s significant coronary disease causing real ischaemia — angina, breathlessness on exertion, reduced exercise capacity, or echo evidence of viable hibernating muscle that would benefit from being revascularised
- Surgery has been declined or carries prohibitive risk, or the patient and Heart Team have agreed catheter-based treatment is the preferred route
- The anatomy is technically accessible to a percutaneous approach — confirmed by a specialist review, not a general one
It’s worth being equally clear about where PCI, including CHIP PCI, isn’t the answer: no significant obstructive disease, terminal illness unrelated to the heart with a short life expectancy, patient refusal of the procedure, or — rarely — anatomy that’s diffusely diseased across every vessel with no usable landing zone anywhere.
What Results Look Like in Practice
In experienced, dedicated CHIP programmes with proper haemodynamic support in place, published outcomes for well-selected patients are encouraging — procedural success rates in the 90% range are commonly reported for complex anatomy, including cases involving prior failed bypass grafts. These figures reflect current-generation drug-eluting stents and structured support protocols at high-volume centres. They don’t transfer to a generalist PCI unit without Impella capability or a dedicated high-risk team — case selection matters as much as technical skill here, and the two go together.
What to Ask If You’ve Been Told Surgery Isn’t an Option
Is my anatomy technically accessible via PCI? This is a question about your coronary anatomy specifically — not your overall medical risk. A surgeon declining bypass doesn’t mean your arteries can’t be stented.
Has a CTO or CHIP PCI specialist actually reviewed my angiogram? General cardiologists and surgeons may not have the specific subspecialty experience needed to judge CHIP feasibility — the right reviewer is a high-volume complex PCI operator.
What haemodynamic support does this centre actually have available? If the honest answer is “IABP only,” that centre may not be equipped for the highest-risk cases. It’s reasonable to ask for review elsewhere.
How much viable myocardium is actually at risk? Nuclear perfusion imaging or stress echo can quantify how much heart muscle stands to benefit. Low burden may mean limited benefit from intervention; high burden usually shifts the risk-benefit case strongly toward treatment.
What does my prognosis look like on optimised medical therapy alone? For low-EF, multivessel patients, this has real limitations worth understanding clearly before weighing it against procedural risk.
If You Have Symptoms Right Now
If you have ongoing chest pain, breathlessness at rest, fainting, or sweating with chest discomfort, seek emergency care locally without delay. This page describes a structured, non-emergency decision pathway — it is not for acute symptoms.
Frequently Asked Questions
Can CHIP PCI be done if my ejection fraction is around 20%?
Yes. An EF of 20% doesn’t automatically rule it out — it determines the level of haemodynamic support needed, and patients in this range typically require Impella-supported PCI rather than IABP alone. The decision depends on a detailed pre-procedural workup, including a viability assessment to confirm there’s hibernating muscle that would actually recover after revascularisation.
Is CHIP PCI an option if a previous bypass has already failed?
Yes — failed grafts after prior CABG are one of the more common reasons patients are referred for CHIP PCI in the first place. The anatomy tends to be technically demanding, working around surgical clips and calcified grafts, but it’s exactly the population this approach is designed for, and procedural success in experienced centres generally stays in the 80–90% range.
How do I know if a hospital is genuinely equipped for CHIP PCI?
Look for Impella availability — not just IABP, intravascular imaging (IVUS and OCT), a dedicated high-risk PCI team including cardiac anaesthesia, and a documented track record in complex PCI volume. It’s reasonable to ask directly how many CHIP PCI cases the operator performs annually and what their support protocol looks like for EF under 30%.
What happens if CHIP PCI is attempted and doesn’t succeed?
If the anatomy proves harder than expected, the team will not push through to the point of causing harm. You receive a detailed written account of what was found and attempted, along with a recommendation for what comes next — sometimes that means revisiting surgical options with better-defined anatomy, sometimes it means optimising medical therapy and reassessing in three to six months.
Patient first. Procedure last.
Dr. Arun Kalyanasundaram, MD MPH FACC FSCAI is a CTO PCI and CHIP PCI specialist at Promed Hospital, Chennai, and Director, Asia-Pacific CTO Club India.
